“The Dow is an unusual index in that it’s price-weighted, so the different stocks in the Dow have dramatically different impacts on the Dow overall,” Colas told CNBC.

For example, Colas described that IBM and 3M have 15 percent of the whole blue-chip index, in terms of impact.

In addition, he noted that Caterpillar is the “entire reason” why the Dow is up on the year.

"CAT’s up about 128 points in terms of contribution—and the Dow’s up about 100," he explained.

At the other end of the spectrum, Colas said firms such as Intel, Microsoft and Bank of America have "miniscule weightings on the Dow," of only 1 to 1.5 percent.

“In fact, you can take the bottom 10 names of the Dow, take them all to zero and you’d open at 8,800—that’s how inconsequential the bottom of the Dow is," he said. "So the top of the Dow is where we’ve got to focus on—we’ve got to look at what the global economy is doing and how we can build some confidence for better demand.”

Colas' 10 Dow Stocks that Matter Most:

Caterpillar

McDonald’s

Boeing

Chevron

3M

P&G

United Technologies

IBM

Johnson & Johnson

ExxonMobil

______________________________ Scorecard—What He Said:

Colas' Previous Appearance on CNBC (Aug. 27, 2010)

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